Lost text formatting in multipart message

Hey there,
I tried to receive the following multipart message:
It contains formatted text and two embedded images, so it should contain 3 mimeparts (text/html,image/gif, image/gif), but there is no text/html-part, only a text/plain part, so the formatting does not exist anymore.
What's the matter and how can I fix it?

You could give
MailKit a try. I designed it to not change the raw message downloaded from the server in any way. When you save it to disk, you get byte-for-byte EXACTLY what was downloaded from the server.

If the message still only contains a text/plain part and no text/html part, then that would suggest that the bug is in the server software.